Micrometer.



W. L. KEEPER.

MIGROMETER.

APPLICATION FILED JUNE 23, 1913.

1,100,573. Patented June 16, 1914.

2 SHEBTSSHBET 1.

W. L. KEEPER.

MIGROMETER.

APPLICATION FILED JUNE 23, 1913.

Patented June 16, 1914.

2 SHEETS -HLET 2.

nmmmto'c "(Zeal #259 67- Wil a mace) attain,

UNITED STATES PATENT OFFICE.

WALTER L. KEEFER, OF FITCHBURG, MASSACHUSETTS.

M ICROMETER.

To all nr/eom it may com-em lle it known that I. 'Anrnu L. Karma. a citizen of the United States. residing at l itcliliurg in the county of 'orccster and State of Massachusetts. have invented certain new and useful Improvenu-nts in Micromet'ers: and I do declare the following to be a full. clear. and exact description of the invention such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to measuring" instruments, and more especially to gages; and the object of the same is to produce an in1- proved micrometer wherein the movable jaw is constantly pressed with gentle force to ward the fixed jaw although it can be retracted instantly by hand and wherein certain advantageous features of construction are embodied, as set forth in the following specification and claims, and as shown in the drawings wherein Figure 1 is a front elevation of this instrunient complete, and Fig. 2 is a similar view with the dial. crystal. and face plate of the casing removed. Fig. 3 is a side elevation of the instrument. and Fig. l is a plan view thereof. Fig. 5 is a vertical section through the casing. taken on the line 5': of Fig. 1. Figs. (5 and 7 are elevations of the plunger from different view points. Figs. 8 and 9 are side elevations of ditl'erent forms of points or jaws. Fig. '10 a detached elevation of the dial.

The frame of this improved instrument comprises a tubular barrel 1 cut away at one point in its side as shown at and a yoke 23 whose upper end is connected with the lower end of said barrel. whose body curves to one side. and whose lower end carries a socket 4 in which is mounted what might he called the fixed jaw or lower point. The barrel carries a casing 5 of cylindrical contour and projecting away from the same on a line preferably at right an; cs to that occupied by the yoke 3. and the back of this casing is closed while its front carries a ringshaped dial 6 having graduation marks over which moves the tip of an index yet to be des ril' cd, the dial being covered by a crystal 7 which is held in place within the casing by a ring 8 or other suitable "1119:1118. The lower point is carried by said socket 4, which is intern ally threaded as at 10 to receive a screw 11 preferably having extremely fine threads so that the accuracy of this instrument may be Specification of Letters Patent. Application filed June 23. 1913.

Patented Jun 0 16, 1914. Serial No. 775.425.

maintained by setting this screw correctly. Vhen the screw is run up within the threaded socket the tip of the screw projects above the same and itself forms the lower point or fixed ja w. ()r. if desired. the screw may be, run downward in the socket whose upper end is forked and the fork arms per forated as at 12. and in that case the pivot pin of a small roller 13 may be. mounted in these perforations and the roller itself will constitute the lowepoint or fixed jaw for I a purpose yet to appear. The movable jaw or upper point is carried at the lower end of a plunger 15. preferably cylindrical. [which moves through the tubular barrel 1 and is provided with a longitudinal groove I [(3 engaged by the tip of a screw or pin 17 in the side of the barrel so as to prevent the plunger from rotatin; therein. One side of this plunger is provided with eraduations as shown at 1 and its upper end has a kn 19. Its lower end is pierced with a trai'isvcrse perforation 20 through which may pass a pin by means of whi h the upper point is detachably connected ith .lltl end. Such point consists of a fixed nn her 21 as shown in Fig. 8 which roacts with the screw ll when the latter is run up in the threaded socket or a socket member 2:} forked at its lower end and carrying a roller 23 iournaled between. the fork arms on a line parallel with the axis of the roller 13. this member c0- acting with the roller member when the latter is employed for the lower jaw.

might say at this point that one of the features of the present micrometer is that. it may be used on a rotating element. such as a shaft. without checking" the rotation there-- of. This is done by means of the carry the rollers whose axe stand in a plane at right angles to that of the yoke 3 shown: but at other times it is possible to use the StiltlOtizHV jaws or jtIW faces 21 and 11, the latter screw.

One side of the plunger 13 with a rack 1 con isting being the upper end of the I teeth, preferably disposed provided of extremely fine at a slight angle to the horizontal. and this rack is so located that it will project throne-h the cutaway porticfi Q of the barrel 1 and into the interi' f the casing 5. Within the latter. in a suitable framework consisting of two plates 30 properly spaced, is mounted a train of gears having extremely fine teeth so that they will mesh with each other and with the rat-k 13 on the plunger: antht while I do not wish to he lntutetl t the! number of the e gears or their teeth or tli.- 1

position, i will tlest-rihe what is iilustrate l in the drawing as typieal ot the tlit'zt i t r earlwlng out my invention. 'l he rat'tt' that as the plunger i pinion 3t is eausetl to limit? tt-u rewi Fast on the shaft oi thipinion it hantl or index 3.7 \Vllit' t liltne \tl the grattuations on the tlial tt. anti a one r roluti-m ot' the hantl intlit'ate. one-tenth ot an ineh the graduations on thi tlial may he v ry lin so that hnntlretlths. thou antiths, aini t-x'en ten-thousautlths oi an inth t-an i e ast't-r tttllttti with ut the we oi gla se th; the

other shit: t' the intit-x iill "tl i! i prel'en al ly tli po e within the i'raiue plate I'M) a gear 36 al o meshing with the pinion it. anti itreli' tlriren i a line eoilt-tl spring 37. The tentlent-y oi this pring is to rotate the spring g ar 30 in Hlt'il tliret-tion that the train of gears will normally tit1)lt.-s the plunger 15. anti l wouitl n.-:l e the streuitit of the spring I57 itar iy uilit-ient to pet-tot in this i'un -tittn so that the operat r ln t i l ut lightly grasp the iinoh 1'.) an i lift the pinn ger to open the jaws wi i r than the artit-le lieine tnea uretl. anti when he re- HHHCS his tingers the tlnt'tiiiiilfj oi the spring 37 restores the parts to their \\'ori in position as will he. t-lear.

Another feature oi tn ill\'ttlti ll is a eoliar lt) which nrrnuntis plunger 15 ahote the upper Uni f the harrel 1. anti is atiiu tahlv mountetl thereon a it hein; split at one t itlt: anti tnrn ti tattnarti into ars it. \\'llit'll latter Ina ie t'iainpeti lt v a tl \lt\\' l2 pas ing through them. The gratluations l-i tprti eraliiy intii atint! ne t nthoi an inch) may he reatl iit'n atit thi t-oiiar an i 2tl)t1\t: the upper entl ot' the harrel a r-t't'll in Fig. l. hut the u e of this t'tlllill is as follows: .\\"lt l|i!] f that th operator is measuring a nuiniier oi ill'li 'il. whit-h are approximat ly one illt'il in tiiatnet r or size. he may :e the t-oiiar to permit the in tru nient to ntt-anre a little untler au in h. an i then -zn'h time it is iii-ought into the he grasps the lt'noh if an i tiraws' the plunger if npwarti only rnili it-ntly to permit the laws to pa s o\'t-r the l iJit'('i ai ter whit-h he rel a-es the hnoh anti the sprint throws the iuws int t' ltttl 't therewith. 'l'h -n. gi-m ne' at the tiiai. h notes the ize in tiicated her t it, after .nhi 'h he ran pull the :niCit-mi 'ter ti l tie arti 'ie anti tilt priug" tlepresrts the plunger until the t-oiiar ill strike: the upper eat! of the iarrel at a point \\i|(l the tlistant'thetw en the jaws oniethin le s than an int-h hut not tnu 'h 'lh -reai ter when he i' ill( to n1ea:-ure the ne\t oiri t he has not i far to rai--e the harrel a it the initt tl t-n tlesteu l to it l w -t e ttr -nii: rnthe iItiiHttt 't f the t tr ugll (\t'ili it wtatltt not ier in an taite lllitt'll t me to i thi i e -ause l t t-an gra p the knoh 1t anti tlraw the pitu rapitlljt' upwartl. rath r than \ttnt-rew'irg it n the ialririons prot' -s t-onnntn to init-reIut-ters new on the market: hut it in Hit net'essanr to tit. e\tn this wh n the t'oilal' i i eniplttjyeti. as he has lllii :t little way to hit the piun .:'er tor the reason inst stateti.

'lhe wring is tltl i proot' antl lllt'iir-iili'( prooi. anti while l have shown a small train oi' gear anti given ti. prel'erretl proportion ol teeth. it will he, elear that any uitahle train oi' gears mijgjht llt entplt t'etl so that the t!!t t'l!ltlll ot the plunger if will he reg" tereti on the tliai. The size anti materials oi parts are not essential, anti the uses of in-trutnent--' of this hintl are too well known to neeti elahoratitai in this Htittiiit'tltillll.

hat. is lainietl as new is:

l. ln'a lliitl' illltitl'. the eoinhinatitm with a t'ranie int-hitting a tuhular harrel, a yoke, anti :1 ti :etl point earrietl lrv saitl yolie in line with aitl harrel. a plunger movable thr u 'h the latter autl ha\ in gratluatieus, a lll Yititlt' point at the lower euti of the plunger anti means l'or pressing the plunger normally towarti the iiXtti point; of a eollar renvahtr anti atljustahly inountetl on the tein oi the plunger ahove saitl barrel and atiaptetl to he Set with re pect to saitl gratinations. tor the purpose set, forth. i

2. in a lnit'rtuneter, the eoinhihatitm with :1 Frame lHiYiIlLI at its lower entl a yoke terlltilltttillL in a threa lett sot-lt'et anti at; its upper entl a barrel in line with aiti sotlcet't the wall ot the sot-icet heingg t'orketi anti llitl'ttti with perl uatitms throu; h the forkar|n anti a lower point illfillltililg a roller whose trunnions are rentovahly engagetl with Filitl peri'orations: oi a plunger inovalile through saitl harrel anti having-a transverse pert ration in its lower entl, anti an upper point :-eino\'ahi v engaged with saiti peri tiitltitnL 3. in a niita'oniet'et', the eoniliination with a l'ralne having a tuintiar hat-rel, a ,yohe, anti :1 tixe i jaw in line with saiti harrel anti a rulier tn untett in saiti jaw on an axis at right angles to saitl write; of a plunger inovt ahie, through saitl lltll'ltl anti having a sot'het,

ntt-Inh r at its inner t-ntl whieh member is i -ritetl at it% inn r twti' inity, anti a roller itllltilitilii "i\\ttlz th i u'it arms, for the pin-p -t-i forth.

1. in a tnitrtaneter the em il ination with lit) I Ilt) a frame including a barrel cut away at one side, a yoke projecting from the lower end of said barrel, and a fixedj aw carried b the lower end of the yoke; of a plunger sli ably mounted throughsaid barrel and having a a frame including a tubular barrel cut away,

at one side, a pin in the barrel, a casing on the frame, a dial on the casing, a yoke projecting outwardly from'the lower end of said barrel, and a fixed jaw carried by said yoke;

of a round plunger slidahly mounted through said barrel and having a groove along one side engaging said pin and a rack opposite said cut-away portion, the body of the plunger being inscribed with a scale, a collar mounted on the plunger above said barrel and adjustably along said scale, a movable jaw at the lower end of the plunger,

indicating mechanism carried by said casing.

over the dial and connected through said cut-away portion with said rack, and yielding means for moving the plunger toward the fixed jaw.

In testimony whereof I have hereunto set my hand in presence of two' subscribing wit-.

nesses.

WALTER L. KEEFER. Witnesses:

JOHN E. MADDEN,

LAURENCE B. SoaNLoN. 

